Multiple-filament lamp



- Sept. 9, 1930.

E. BONDIEK 1,775,187

MULTIPLE FILAMBNT LAMP iled Nov. 25. 1927 26 x ZZ \\I x Q. 79 24 xavwemto'c irmesf Eonoliek Patented Sept. 9, 1930 PATENT OFFICE ERNESTBONDIEK, F GUTTENBERG, NEW

MULTIPLE-FILAIEENT LAMP Application filed November 25, 1927. Serial No.235,529.

My invention relates to improvements in incandescent electric lamps orlight bulbs in which a pair of filaments or a double filament is usedallowing to utilize a new fila- 6 ment if one is ruptured or burnt out,or a lamp which at times, when it is desirable to have a very brightlight, allows to increase the intensity of the light produced by asingle bulb by utilizing both filaments,

and it is the principal object of my invention to produce these effectsby a single manipulation of the light bulb.

Another object of my invention is the provision of a lamp ofthis'character which is extremely simple in its construction andtherefore inexpensive and which produces a great saving in material, aswell as in labor.

A further object of my invention is the provision of an incandescentelectric lamp which may be used for a relatively along period, which maybe readily manipulated by anybody, even persons not skilled in the art,to disconnect one of the filaments from the circuit for remaininginactive while the other is active or to connect both filaments in theenergized circuit if it is desired to increasethe intensity of the lightproduced by the bulb by a simple turn of the bulb. This is particularlydesirable in bulbs for electric sign boards, where it will simply benecessary if one filament is broken to turn the lamp farther into itssocket to make the lamp glow again, without the necessity of exchangingthe bulbs, this resulting in a great saving of labor and material.

It will be evident that by designing the lamp for heavy or high wattage,each filament may be for instance of 100 watt intensity, and thus, whenboth filaments are ener- 49 gized a 200 watt bulb will be provided. Thisis naturally cited as an example only,

as evidently any desired and suitable watt in-" tensity from the lowestto the highest possible may be employed.

Moreover, the two filaments may be of equal or unequal resistanceaccording to use of the lamp for domestic or home illumination, or forinstance in cars or the like, and if one of the filaments is of lowresistance,

the lamp may be used for night lamp service,

guided through the base.

while it may be used for reading etc., purposes by simply cutting bothfilaments in through screwing the lamp base entirely into the lampsocket.

These and other objects and advantages of my invention will become morefully known as the description thereof proceeds and will then be morespecifically defined in the appended claims.

In the accompanying drawing forming a material part of this disclosureFig. 1 is a side elevation of the electric light or lamp bulbconstructed according to my. invention, and illustrating an exteriorview of the same.

Fig. 2 is a sectional view of the light bulb, part of'which is brokenaway to lllustrate its interior construction. I

As illustrated, the lamp com rises a bulb 10 of any desired shape and coor or trans parency which is hermetically sealed in the usualmannerandcementedtoits base 11. The outer metallic shell or screw contact isdesignated 12, and is made in two parts, the upper one being separatedfrom the lower part 13 by means ofan insulated portion 14, and a similarart of insulating material 15 is provide on top'of the base and shell.

The sleeve 16 is embedded in the, solid end ofthebase and has a centralopening into which movably engages a contact member 17 having a flangedlower end 18 for holding and -ding member 17 in the sleeve and forlimiting its outward movement. This memberis adapted-to engage thecentral contact of a lamp socket.

The upper end of the filament 19 connected with. the positive pole of alight socket, is formed into a spiral leader 2O electrically orconductively connected at its end, as at 21, and the end of the filamentconnected to the negative pole, designated 22 is conductively connectedto the shell 12, as at 23, after being A second fila' """nt 24 isconnected to the filament 19 and is guidedgupwardly through part of thebase and conductively connected to part 13 of the shell,as at 25.

It will be clear'that the filaments illustrated on the drawing areintended to illusread on hand of the drawing and it will be evident thatby screwing the bulb in the usual well known manner into a lamp socketso that contact member 17 just engages the socket contact and shell 12,only is in contact with the socket walls, a circuit will be closed overthe socket contact through filament 19, filament 22 to shell 12, andonly this filament will glow.

If this filament is ruptured, the lamp bulb I need simply be turned topress member 17 inwardly and compress the spiral or helical leader,while shell-part 13 of the shell comes into' contact with the socketwall, the circuit will be closed over filament 19, filament 24 andshell-part 13, and filament 24 will glow.

It will be clear that both filaments will be energized to glow, if theshell is entirely screwed into the lamp socket at the beginning, whenbothfilaments are intact.-

It is to be understood, that I have shown and described as an example ofthe many possible ways to practically construct my lamp bulb, thepreferred form thereof, and that I may make such changes in the generalarrangement and in the construction of the minor details, as come withinthe scope of the appended claims without departure from the spirit of myinvention and the principles involved.

Having thus described my invention, what I claim as new, and desire tosecure by Letters Patent is 1. The combination withan electric lampprovided with a plurality of filaments, of a base and its shell, saidshell having separate portions insulated from each other to whichcertain of said filaments are connected at one end, a sleeve projectingfrom the said base, said sleeve having an end wall provided with aspring contact member movably held in said sleeve, 2 flange at the innerend of said contact member for limiting the outward movement of thesame, and a means connected to the other end of said filaments withinsaid sleeve and contact member for ensuring a conductive contact betweensaid member and a lamp socket in all positions of said base and itsshell in said socket.

2. The combination with an electric lamp provided with two filaments, ofa base and its metallic shell, said shell adapted to be screwed into alamp socket, and having separate portions insulated from each other towhich said filaments are connected at one end, a sleeve projecting fromsaidbase, said sleeve havingan end wall providedwith 3.

spring contact member movably held within said sleeve for verticaldisplacement therein, and a flange at the inner end of said contactmember for limiting the outward movement of said member, and a coilformedat the end of the other of said filaments tending to press

